Simantics System Dynamics
System dynamics is a methodology for understanding the behaviour of complex dynamic systems belonging to different domains. Simantics System Dynamics is a free, open source system dynamics modelling and simulation software. The software has an intuitive and easy to use Eclipse based graphical user interface which allows you to configure the whole model structure graphically. In addition to supporting all the common system dynamics modelling operations, the software includes many advanced features, such as structural reusable components, multidimensional variables, and sensitivity analysis.